A peak detector

Ac voltage to DC voltage and reduces the disturbance. The function can be explained as follow. The capacitor stores the current peak voltage.If he input voltage is larger, the op-amp output goes positive until the capacitor is charged up to the new peak value. If the input voltage is smaller, the diode keeps the capacitor from being discharged. This peak value of voltage that is stored on the capacitor will remain until this capacitor is discharged by a mechanical or electronic switch. Components of peak detector circuit Peak detector circuit consist of two operational amplifiers (op amps), by first op amps on diode Dn is connected in parallel manner and another diode Dp is connected in series manner.And this op amp is connected to the voltage supply. Another op amp and capacitor is connected with this circuit in series. A reset switch is added to the circuit by which the value of peak value that is stored on capacitor A resistor is connected between two op amps. When choosing the re sistor, the limits must be considered: rdf 12 l/fc, where fm is the modulation Frequency and fc is the carrier frequency. Working of peak voltage circuit: The typical peak detector uses voltage amplifiers and a diode or an emitter follower to charge the hold capacitor, CH, unidirectional.The diode conducts positive half cycles, charging the capacitor to the peak voltage value. When the input waveform falls below the DC peak voltage value stored on the capacitor, the diode is reverse biased, blocking current flow from capacitor back to the source. Initially the capacitor discharge(O V) by resetting the A that is negative in situation, Dp blocks current, TOB current is provided by 10 ohms and diode reverses leakage from drain capacitor and stop the output signal. If input inverting input exceed the voltage of the capacitor, he output of B races up to a positive value and current flows through Dp .The voltage drop of the diode is negated due to feedback voltage being after the drop. Th e capacitor charges until it has reached Vin or when Vin drops below its capacitor's voltage at the time of which A goes back into the negative saturation. The capacitor slowly discharge through the reset. This is a major source of droop on fast or low duty cycle signals since it will discharge some before. The next wave peak A- is a unity gain output buffer that prevents the next stage from draining the capacitor.